by Dava Sobel
Peace put Copernicus briefly back to work on the more mundane matters of administration. In May 1521 he oversaw the reassignment of land parcels made vacant “by the death of Michel the one-eyed,” “by the beheading of Peter in Hoensteyn for plotting treason,” and for a variety of other reasons. Both the peasants and the land had suffered war losses.
In June the chapter called Copernicus back to Frauenburg to restore normal order in the north, while his capable friend Tiedemann Giese took over at Allenstein. Giese’s new term as administrator—this was his third—proved the most difficult of his career. Despite the peace treaty, the knights continued laying waste to Varmia. And yet, because of the peace treaty, the chapter could not fight back. Giese wrote petitions for redress of grievances. He made impassioned appeals for peaceful relations at summit meetings between the Prussian Estates and the Teutonic Order. Nothing, it seemed, would dislodge the knights from the city and environs of Braunsberg, which they had occupied since the start of the recent war. Still Giese persisted in his negotiations. Both the king and the bishop promised to support him at the summit planned for Graudenz in March 1522. Sigismund would send his emissaries, and Fabian would attend in person. In the event, however, the bishop was too ill to leave his bed, so he sent his physician, Doctor Nicolaus, in his stead.
Copernicus joined Giese in Graudenz, only slightly delayed by flooded bridges over the River Bauda that all but barred his way out of Frauenburg. On March 18, he stood with Giese before the assembled representatives and seconded his enumeration of the knights’ abuses. Three days later, he delivered the treatise on coinage that he had conceived before the war, chastising the minting practices that had sent the currency into free fall.
“The worst mistake,” he charged, “which is absolutely unbearable,” is for the government to mint new coins—of inferior intrinsic worth, though pretending to equal value—while the old coins are allowed to remain in circulation. “The later coinage, always inferior in value to the earlier coinage, … constantly depressed the market value of the previous coinage, and drove it out.”2
Copernicus compared the infusion of inferior coinage to the sowing of bad seed by a stingy farmer. The government, like the farmer, would reap exactly what it sowed, he said, since its practices damaged the currency as surely as blight ruined grain.
“Such grave evils, then, beset Prussian money and, because of it, the whole country,” he continued. “Its calamities and decline benefit only the goldsmiths, who take the value of the money into their own hands.”
To remedy the situation—“before a greater disaster!”—Copernicus recommended a consolidation of the mints, so that “only one place should be designated for the minting of money, not for a single city or under its emblem, but for the entire country.” Mint no new money in the interim, he further counseled, and above all set strict limits for the number of marks to be struck from a single pound of fine silver. Then, as soon as the new currency is introduced, prohibit the use of the old, so as to force the surrender of outdated coins for new ones—at a loss, yes, but only a slight one. “For, this loss will have to be suffered once, in order that it may be followed by many benefits and a lasting advantage, and that a single currency reform in 25 or more years may be enough.”
His suggestions sounded even more relevant now that Sigismund wished to unify the disparate currencies of his kingdom. In order for the Polish Crown coins and Prussian monetary systems to be reconciled, a firm rate of exchange had to be established among them. Copernicus immediately produced an addendum to his treatise while still at the March 1522 meeting, outlining a specific plan to equalize the currencies. But the assembly ended without changing the status quo, either of coins in the realm or the knights ensconced in Varmia.
Grand Master Albrecht had condoned the minting of inferior Prussian coins from the moment he took over the Teutonic Order in 1511. Nevertheless, the high cost of war had put him on the brink of bankruptcy. Albrecht betook himself to Germany in 1522 to attend the Diet of Nuremberg, where he hoped to acquire new allies—and sufficient cause to break the peace with Poland. At the Diet, Albrecht met one of Martin Luther’s disciples, a former Catholic priest named Andreas Osiander. As an avowed convert to the new evangelical Lutheran faith, Osiander set about convincing Albrecht to convert as well. Albrecht then went to Wittenberg to seek out Luther for further consultation. The now famous heretic, excommunicated by Leo X in 1521, likewise urged Albrecht to end his allegiance to the Catholic Church—and also his allegiance to the Order of Teutonic Knights. Luther thought it preferable for Albrecht to appropriate the knights’ side of Prussia as his own, find a wife to rule it with him, and raise a family dynasty to inherit his privileges. As Albrecht began to explore these intriguing avenues, his ten-year enemy, Fabian Luzjanski, the Bishop of Varmia, died of syphilis on January 30, 1523.
Coins from the reign of Sigismund I.
Copernicus, who had shunned the easy road to the bishopric that his uncle once paved for him, now found himself presiding at Heilsberg Palace. The chapter chose him to watch over all the lands of the diocese, including those appertaining to the bishop’s see, until Fabian’s successor was installed. Given the rancor that had surrounded the selection process after Bishop Watzenrode’s passing, King Sigismund sent his envoys to Heilsberg in February to foil any preemptive election attempts by the chapter. Copernicus received these men with assurances that the canons would not only honor the king’s right of nomination and approval, but also swear their allegiance to him anew under the next bishop, whosoever that might be.
On April 13, the chapter chose the king’s favorite, Maurycy Ferber. Bishop-elect Ferber, a distant relative of Tiedemann Giese, belonged to a politically powerful family from Danzig, where one of his kinsmen currently served as mayor of the city. Pending papal approval of Ferber, Copernicus acted as de facto bishop all through the spring and summer of 1523. He struggled to restore law and order by ridding the region of recalcitrant knights and the rear guard of the Polish military. The very forces who had come to Varmia’s defense now illegally occupied several villages and fortresses. They refused to leave until the king intervened. Following Sigismund’s orders of July 10, all Polish commanders of troops squatting in the diocese finally relinquished their claims and decamped. The knights, however, remained.
In August the Moon turned red—not as a metaphor for blood or war, but actually and naturally, as the result of a total lunar eclipse. Copernicus noted the first dip of the full Moon into the cone of the Earth’s shadow at “2 and 4/5 hours past midnight,” or 2:48 A.M. on August 26.
Traversing the shadow of the Earth, the Moon dimmed by degrees until fully immersed. Then, instead of disappearing in darkness, the eclipsed Moon daubed itself with the Sun’s color: It glowed like an ember throughout the hour of totality, reflecting all the dusk and dawn light that spilled into Earth’s shadow from the day before and the day ahead.
Copernicus never missed a lunar eclipse. No astronomer let such an opportunity slip, for the Moon in eclipse pinpointed celestial positions as no other phenomenon could. At such times the Earth’s shadow became visible on the Moon’s surface, and the center of that shadow indicated the location of the Sun—180° opposite in celestial longitude. With the Moon’s current coordinates thus confirmed, one could also measure the distances of stars and planets from either the Sun or the Moon. “In this area,” Copernicus remarked, “Nature’s kindliness has been attentive to human desires, inasmuch as the Moon’s place is determined more reliably through its eclipses than through the use of instruments, and without any suspicion of error.”
Even with the help of “Nature’s kindliness,” the tilt of the Moon’s orbit relative to the Earth’s great circle limited the frequency of lunar eclipses to once or at most twice a year, though some years have none. After August 26, there would not be another total lunar eclipse till the end of December 1525.
At the moment of mid-eclipse, which Copernicus recorded on this occasion as 4:25 A.M., the Mo
on stood at opposition, yet stayed its course straight ahead. Unlike Jupiter or Saturn, the Moon never shifted into reverse at opposition—or ever, at any time—because the Moon, alone among all heavenly bodies, truly did orbit the Earth.
“In expounding on the Moon’s motion,” Copernicus wrote, with no apparent irony, “I do not disagree with the ancients’ belief that it takes place around the Earth.”
THE VALUE OF ECLIPSES
Johann Stoeffler’s Calendarium Romanum magnum , published in 1518, predicted eclipses for the years 1518 to 1573. Copernicus annotated his copy with his own observation notes between 1530 and 1541. The special alignment of Earth, Moon, and Sun at eclipse, called syzygy, provided a natural check on celestial positions. Copernicus witnessed both partial and total lunar eclipses, but only partial solar ones. Had he been able to travel to Spain or to the southern extreme of Italy for the April 18, 1539, event, he might have seen the Sun totally eclipsed.
Ptolemy had reported in the Almagest how he derived the Moon’s motion by tracking it through three eclipses of similar duration and geometry. Copernicus was following suit by observing his own three eclipses: one through the midnight hours of October 6–7, 1511; a second more recently, on September 5–6, 1522; and the third in the triad on this night, August 26, 1523. With these data, he meant to reroute the Moon.
On the path Ptolemy had charted centuries earlier, the Moon altered its distance from Earth so dramatically over the course of the month as to make it appear four times larger at its closest approach than at its most distant point. Observers never saw the Moon do anything of the kind, however. Its reliable diameter barely ever changed, yet Ptolemy and most of his followers ignored that glaring fact. Copernicus addressed the discrepancy by offering an alternate course that preserved the Moon’s appearance.
On October 13, Bishop Ferber at last assumed his rightful position, freeing Copernicus to return to Frauenburg. The chapter elections in November named him chancellor once again, but he did not expect the duties of office to impede his astronomical researches or the writing of his book any longer. At fifty, he could only guess how much time remained for those pursuits, before the inevitable loss of his stamina, or his eyesight, or the clarity of his mind.
Chapter 5
The Letter Against Werner
Faultfinding is of little use and scant profit, for it is the mark of a shameless mind to prefer the role of the censorious critic to that of the creative poet.
—FROM COPERNICUS’S Letter Against Werner, JUNE 3, 1524
The great Conjunction of 1524 brought Jupiter and Saturn together in the sign of Pisces. Astrologers, who classified Pisces as a watery sign, predicted the dread disaster at conjunction would take the form of a mass drowning, indeed, a global inundation to rival Noah’s flood. Every Jupiter-Saturn union blew an ill wind, but this one’s evil potential drew added force from the number of other heavenly bodies convening with the main two. On February 19, Copernicus’s birthday, the planets Jupiter, Saturn, Mars, Venus, and Mercury would all cluster together with the Sun in a grand sextuple conjunction, followed by a full Moon that night. Further proof of apocalypse derived from Pisces’ rank order as the twelfth and final zodiac sign. Given that astrologers believed the world had begun under a multiplanetary conjunction in Aries, the first sign, surely it would end now under a repeat occurrence in Pisces, the last. The growth of both printing and literacy helped spread these dire prognostications so far and wide that people living in coastal regions took to the mountains. Some looked to their Bibles for instructions on how to build an ark.
February passed, and no floodwaters rose. Disbelievers scoffed at the astrologers, who held firm that waves—if not of water, then of religious dissent or political unrest—would yet wash over Europe. Had not the Great Conjunction of 1345 required two years to unleash the Black Plague?
Copernicus, who neither issued nor heeded astrological forecasts, chose this moment to pursue a bad debt. Canon Henryk Snellenberg, who had been his sole comrade in arms during the final defense of Allenstein Castle, went to Danzig and, as a favor, collected some money owed to Copernicus by his cousin on the city council there. But when Snellenberg returned to Varmia, he turned over to Copernicus only ninety of the hundred marks the astronomer’s cousin had paid. Snellenberg repeatedly put off the reimbursement of the remaining ten marks, making one excuse after another over a period of months. When Copernicus finally confronted him, Snellenberg demanded written proof of the debt, and then dared his creditor to file suit for the sum still owed. Sufficiently grieved, Copernicus complained to Bishop Ferber.
“I therefore see that I cannot act otherwise,” he wrote to his superior on February 29, “and that my reward for affection is to be hated, and to be mocked for my complacency. I am forced to follow his advice, the advice by which he plans to frustrate me or cheat me if he can. I have recourse to your Most Reverend Lordship, whom I ask and beseech to deign to order on my behalf the withholding of the income for his benefice until he satisfies me, or a kind provision in some other way for me to be able to obtain what is mine.”
In comparison to the petulant but principled tone of his complaint against Snellenberg, the content of another letter Copernicus wrote that same year, on June 3, 1524, contained an invited analysis of such interest to the mathematics community that multiple copies of it circulated among his peers. Although terse and informal, the Letter Against Werner stands alongside the Brief Sketch and On the Revolutions as the third pillar of Copernicus’s oeuvre in astronomy. He addressed it “To the Reverend Bernard Wapowski, Cantor and Canon of the Church of Krakow, and Secretary to His Majesty the King of Poland, from Nicolaus Copernicus.”
GREAT CONJUNCTION OF 1524
The combined presence of Jupiter and Saturn—along with several other celestial bodies—in the twelfth zodiac sign, Pisces (the fishes), struck dread in the hearts of astrologers, who forecast the floodwaters shown pouring from the exaggerated sky-fish in this image from Leonhard Reynmann’s Prognostication for 1524.
Wapowski and Copernicus had attended the Collegium Maius in Krakow together as undergraduates in the 1490s. Possibly they developed their shared interest in planetary theory at that time, perhaps even in each other’s company. Wapowski, who also went on to study law at Bologna, had later served several years in Rome with the Polish embassy, and now communicated with an international coterie of intellectuals. Copernicus alluded to the closeness of their long-standing friendship in his Letter’s first sentence.
“Some time ago, my dear Bernard, you sent me a little treatise on The Motion of the Eighth Sphere written by Johannes Werner of Nuremberg.” Wapowski had sought Copernicus’s opinion of this widely praised paper, which was published in 1522 along with several other recent essays by the same author. Copernicus hesitated before complying, however, because he found fault with Werner’s thesis and was not at all sure he should say so. Now he excused himself to his old friend for the long delay.
“Had it been really possible for me to praise it with any degree of sincerity, I should have replied with a corresponding degree of pleasure.” Unfortunately, the highest compliment he could offer—“I may commend the author’s zeal and effort”—took him “some time” to muster. At first, he admitted, he feared arousing anger by expressing censure in writing. Better, perhaps, to say nothing at all against Werner than risk a negative backlash that might ruin any chance of a favorable reception for his own work.
“However, I know that it is one thing to snap at a man and attack him, but another thing to set him right and redirect him when he strays, just as it is one thing to praise, and another to flatter and play the fawner.” In the best spirit of correcting a fellow astronomer’s misstep, then, he would share his thoughts. He did not know that Werner, a clergyman at a Nuremberg infirmary, had died of the plague in 1522 while his papers were still on press. “Perhaps my criticism may even contribute not a little to the formation of a better understanding of this subject.”
The “eighth
sphere” of Werner’s title spun the stars. They were all embedded in it, like jewels in a crown. This placement accounted for the way the stars retained their fixed positions vis-à-vis one another, each in its own constellation niche, even as the heavens revolved around the Earth every day. While rolling rapidly westward, however, the eighth sphere also betrayed a slow, subtle drift in the opposite direction, which astronomers had long sought to explain. In Copernicus’s cosmos, in contrast, the eighth sphere remained stationary. It only appeared to move because of the Earth’s rotation. But rather than raise this fundamental difference in his critique, Copernicus focused on Werner’s technical mistakes.
“In the first place, he went wrong in his calculation of time.” Werner had bungled a conversion of Egyptian calendar dates to Julian chronology, so that he assigned certain observations by Ptolemy to the year A.D. 150, when in fact, Copernicus demonstrated, Ptolemy had made those observations eleven years earlier, in 139. Then Werner compounded his initial error by accusing Ptolemy and other ancient astronomers of sloppy observing technique. Here Copernicus lost his temper:
